For well over a century, a bicycle has been a mode of transportation used both by adults and children. However, for adults, a bicycle may be a transportation of choice, not of necessity. However, for many children, a bicycle is the only way to go from place to place other than walking. Bicycles are largely stereotypical in their construction and operation. Ordinarily, there are two tires connected by a frame. The motive power is provided by the rider using pedals, crank, sprockets, and a chain mechanism that allows the user to push the pedals in a largely straight line or slight arc-like motion. The crank, chain, and sprockets translate this straight line motion into a circular motion, which is then applied to the rear wheel of the bicycle to cause it to rotate, hence moving the bicycle along a path chosen by the rider. The rider steers using the front wheel with a handle bar, mounted in a pivoting relationship with the frame and the front wheel. A bicycle is not self-balancing—that is, if one places a bicycle in an upright position and removes support from the bicycle, it will fall on its side. Consequently, the act of learning to ride a bicycle is a relatively complex one. It requires that a user control the steering of the bicycle, pedal the bicycle, all while maintaining the user's balance on the bicycle. While not unduly difficult to learn, it is a process that takes some time and may result in some falls, or even injuries, to a user. Consequently, the standard method of teaching riding a bicycle involves a parent or other person standing nearby or touching the beginning rider who is placed on the seat of the bicycle and the pedals. The supervising individual holds the rider upright and the rider learns to pedal and steer while receiving support from the individual. At some point, the support is removed and it is hoped that the rider is then able to balance and steer the bicycle.
However, “training wheels” are another training expedient sometimes employed. This training device consists of two wheels which are temporarily mounted on the rear bicycle axle and extend outwardly from the rear wheel to provide extra support, substituting for the extra support provided by a supervising individual as described above. However, as with many temporary expedients, this is not entirely satisfactory. The training wheels have to be installed on an existing bicycle. They are not entirely effective at preventing a fall or a wreck on a bicycle when in use and they have a certain stigma attached to them for the child who may be learning to ride using training wheels.
Part of the problem that arises with a regular bicycle when used for training is caused by the function of the bicycle. In order for an individual to be able to effectively pedal the bicycle, the pedals need to be a certain distance from the seat, so that as a person is making the pedaling motion, the legs come close to fully extending. If the legs are unduly bent or cramped, it reduces the power available for the pedaling stroke. Consequently, if the seat is mounted at the proper height on a bicycle, a user is ordinarily not able to place both feet on the grounds at the same time without dismounting from the seat. Consequently, for an inexperienced user on a regular bicycle, if the bicycle begins to tip, the tipping may reach an uncontrollable point before the user is able to transfer their feet from the pedals to the ground to provide support. Adding training wheels to a conventional bicycle does nothing to overcome this problem.
Another mode of transportation is a two wheel scooter. This differs from a bicycle in that the mode of power is provided by the legs of the user pushing along the ground. When using a scooter, a user stands on a flat panel supported at each end by the scooter wheels. Usually the front wheel pivots for steering. Unlike a bicycle, a scooter user stands when in use rather than sitting on a seat as is the case with a bicycle. Scooters are usually used on flat ground and for travel over short distances. However, their utility is limited for people who have balance problems or people who, for some reason, may need to rest their weight on a seat when not using their legs for motive power.